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PATENTED JAN. 28, 1868.

LPE. RIVOT. METHOD OF AND MEANS FOR TREATING ORES OF GOLD AND SILVER.

4 SHEETS-SHEET 1- Wiineaurw PATENTED JAN. 28, 1868.

L. E. RIVOT. METHOD OF AND MEANS FOR TREATING ORES OF GOLD AND SILVER.

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THE nonms PETERS co, PHOTOLITHO, msmnm'c PATENTED JAN. 28, 1868.

L. E. RIVOT. METHOD OF AND MEANS FOR TREATING ORES OF GOLD AND SILVER.

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PATENTED JAN. 28, 1868.

1.. E. RIVOT. METHOD 0E AND MEANS FOR TREATING OBES OF GOLD AND SILVER.

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LOUIS E DOUARD RIVOT, OF PARIS, FRANCE, ASSIGNOR TO JACQUES GAILLARDON, OF SAN FRANCISCO, CALIFORNIA.

Letters Patent No. 73,888, dated January 28, 1868.

IMPROVED METHOD AND MEANS FOR TREATING- ORES OF GOLD AND SILVER.

TO WHOM IT MAY CONCERNi Be it known that I, LOUIS EDOUARD RIVOT, of Paris, in the Empire of France, have invented certain new and useful Improvements in the Method of and Means for Treating Auriferous and Argentiferous Ores; and I hereby declare the following to be a full, clear, and exact description of the same, reference being bad to the accompanying drawings.

This invention relates to certain improvements upon the invention, for which Letters Patent of the United States were issued to me on May 31, 1864, No. 42,997, and it. relates more particularly to the'method of roasting and amalgamating thoreinreferred to.

Ii Roasting. The roasting is effected exclusively by steam, injected into or upon the ore at'a high temperature -the are being heated to or above a dull red. Experiments made in California have indicated the ject of the present patent. They relate- V 1. To a novel arrangement of the roasting-furnace, in which the ore is entirely separated from the flame by means of cast-iron plates, but in which the steam is always superheated on an independent apparatus.

2. To a novel arrangement of two reverberating furnaces, with one and with two firc-chnmbcrs, in which the ore is likewise separated from the flame by cast-iron plates, and in which the superheating of the steam is necessity of introducing certain modifications in the furnace and steam suporheating, which constitute the subeffected by the flame derived from the fire-chambers.

3. Toan arrangement of two reverberating furnaces, one a wood-furnace, the other a coal-furnace, which are like that described in my patent of 1864, with the addition of a steam-superheating arrangement within the furnace itself. i

I. The new furnace, which is shown in Sheet I of annexed drawings, allows of the complete roasting of the ore being effected by steam alone with great facility. The dimensions shown in thedrawings are calculated for a furnace taking at least five hundred kilogrammes at a single charge. I give this simply to indicate the proportions of the divers parts of the furnace. I wishto have it understood,however, that the dimensions may be varied according to circumstances and convenience. The figures represent two furnaces in juxtaposition, a convenient arrangement, whereby one workman can attend two furnaces. The two furnaces being alike, I shall describe but one. The fire-doors are shown on the supposition that the fuel used is wood, and it will be easy to modify them in case other fuel'bc used.

Figure 1 is a horizontal section on lines 1, 2,3, and 4, fig. 2; that is to say, a section of one ofthe furnaces on a level with the seven tuyeres which inject the steam, and a section of the other furnace, on a level with the flues through which the flame is conveyed to the chimney. I

Figure 2 represents a vertical central section of the second furnace, on line 5 6, fig. 1.

Figure 3 is a long section of one of thefurnaces through the centre of the arch, that is, on lines 78, fig. 1.

Figure 4 shows one of the furnacesin side elevation, on the side where the furnace is charged, and the workman stands. The other furnace is shown in vertical section through two flues on lines 9 10 11 12.

Figure 5 represents a side elevation of one of the furnaceson the side of the fire-door and tuyeres, and a vertical section of the second furnace, through the centre of the flues, which convey to the chimney the flame from the fire-chamber, and products due to the action of the steam on the ore, that is to say, on line 13 14,,and 15 16, fig. 1.

The operation of the furnace is as follows: The fuel is charged through the cloorp into the fire-chamber)",

and the flame follows along the arch of the furnace, descends through thesix flues, c, which pass horizontally .under the sole of the furnace, and are ejected through the chimney B by passing through the angular flue A.

The sole is laterally confined by two brick fire-bridges, which support horizontal cast iron plates. The position of those plates is indicated in figs. E. and 3. The joints between the plates may be sealed by means of a fusible silicate, so as to effectually exclude the introduction of the flame into the space comprised between the plates, the sole, and the two bridges. This space constitutesa muflie, in which the ore is heated at pleasure by reverberation from the cast-iron plates, at the same time that it-is protected from the flames in the fire-chambcri At one of the extremities of the flll'llflu, which is closed-by a brick wall, superheatedsteam is received from seven somewhat inclined tuyeres, at a pressure of about one atmosphere above the ordinary atmospheric pressure. The arrangement of the brick wall, tuyeres, steam-pipe, and arch whichsupport the masonry is clearly shown in the drawings. Thcsteam-pipe should be provided with a valve to regulate the admission of steam; the llfllb'ei however, is not shown in the drawings. I would observe that in pla'ce'of the pipe which is provided with the seven tuyeres, there may be used a horizontal pipe within the furnace, having flattened orifices, through which steam may escape in a continuous sheet throughoutthe whole width of'the furnace. The ore may be charged either through a hopper in the centre andabovc the arch, or by means of shovels through the door P. The pi'oducts-of the action of the steam upon the ore descend through the two fiues I into the chamber K. The noncondense d products pass into the chimney through the angular flue G. Two openings are formed in the masonry for the cleansing of the tines I and A. These openings are closed with bricks during the operation. The rabhling and the discharging are effected through the door 1?, for which'such closing-device may be'used as deemed expedient; for instance, such as are used in puddling-furnaces, the essential point being, that in introducing the rabble or other instrument, as little air as possible should be allowed to penetrate. -That part of the furnace which comprises the working-door is so continued that the cast-iron plates can be easilyreplaced without demolishing any essential part of the furnace. The permanent brick masonry is supported by arches, V, which abut on piles whose faces are parallel with those of the two bridges. The arches are higher than'the plates when in position, which allows of their beingeasily put in place; When the plates are properly set, the brick masonry is built as shown in figs. 1 and 4. This masonry, which I shall call temporary, is removed and replaced every time it is necessary to renew the plates. It has for a foundation the iron plates, whose prolongation constitutes the working-plates. Each plate is pierced with two square openings, corresponding to the two flues I. These openings are arranged to receive two cast-iron caps, which close the dues during the charging and discharging. The lower arched chamber K communicates with theloutside by means of an arched way, T, which is closed by a door, through which the chamber can be cleaned when necessary. The water of condensation runs off through a drain, pipe, or gutter under the sole. The room in front of the door necessary forcleuning out the chamber is covered by boards placed on beams. Thus one is enabled to easily work on the furnace to bring to the door the-material or charge, and the wheel-barrow or cars in which the elaborated ore is dropped at the end of each heating. I v

The operation in the above-described furnace is the same as that in-the reverberating furnace described in my patent of 1864. It is, therefore, unnecessary further to describe it. The same observation is applicable to the furnaces hereinafter described.

2. The reverberating furnace with cast-iron plates. The same result, z'. e., the separationof the ore from the flame of the fire-chamber, is'attained by modifying the reverberating furnace described in my 1864 patent. To this. effect, cast-iron plates are introduced ona level with the bridge, and let into the side walls from one extremity of the furnace to the other. In thisway considerable economy of fuel is effected in super-heating. the steam by means of the flames from the fire-chamber. v

The drawings, Sheets II and III, represent afurnace with one fire-chamber, and one with two fire-chambers,

each provided with cast-iron plates. I shall describe a furnace with reference to wood as fuel. It will beeasy to modify the arrangement if it be necessary to use other fuel.

The reverberating furnace with one fire-chamber is shown in Plate II. In said drawing-- Figure 1 represents a horizontal section on line 1 2 3 4 5 6, fig. 2,' i. e., a little below the'cast-iron plates as to the sole and fire-chamber, and a. little above the steam-plates as to the bridge. I

Figure 2 represents a vertical section on the line 7 8 in fig. 1- I p v Figure 3 is a rear view of the cast-iron plates, above which the flames from the fire-chamber pass. It is represented'on a scale double that shown in figs. 1 and 2, in order to show to better advantage the arrangement or the cast-iron plates. t 7

Figures 4 and 5 are on the same scale as fig. 3: The former is a vertical section of the cast-iron plates in the direction of the length of the furnace, t. e., perpendicularly to the length of the plats. Fig.5 is avertical section on the line 9 10, fig. 3, 2'. e., through the axis of the second working-door,and represents the arrangement of that door.

The fuel is charged through the doorp into the fire-chamber]. The flames directly heat the four cast-iron tubes g. g{ g 9', in which the steam circulates, and follow' the arch, heating directly and by reverberation the cast-ironplates, and finally pass into the chimney through the two flues c c. The air necessary for the combus tion enters the chamber under the grate through the opening A, which is as wide as the grate, and as high as the ash-pit. The opening is closed a small brick wall, a, in which apertures are formed, provided with sliding doors. The object of this arrangement is to regulate atwill the amount of air which enters under the grate, and consequently to economize the fuel. The sole is separated from the flames by cast-iron plates, which rest on the side walls and on the bridge, and they overlap each other from four to five centimetres. Care should be taken to maintain the necessary spaeein every direction for the expansion of the plates. The separation of the flame from the on placed on the sole is perfected by packing thejoints with a cement fusible at red heat; for instance, a. cement composed of clay and alkaline salts.

The diameter of the tubes 9 g g" g, in which the steam circulates, varies according to the quantity of the ore on the sole. For a charge of, say, five hundredkilogrammes of ore, the diameter of the tubes should be sixteen centimetres. The tubes are laterally held by means 'of the brick walls of the furnace, and the elbows which unite one tube with another are protected from the action ofthe flame by these walls, and are enclosed,

within boxes of sheet iron, encased in the masonry. The two boxes D D are filled with sand, which prevents the loss of heat. The steam enters the first tube g,'and'passes thence through tubes g'g"g, and finally passes through tube'G, which is placed a little above the sole, and pierced 8 Whole length with mouthed orifice, of about one centimetre in width. The steam passes through this orifice in a. regular sheet over the ore spread out on the sole. Steam in excess, and the gaseous products of the action of the steam, pass into the chimney through the two fines c a. By means of the register-valve R, the draught in the furnace is regulatcd. This register-valve may be placed at the top of thc'chimncy, as well as at the entrance to the chimney, as shown in fig.'2. The twoorifices o 0 in the solo opposite thoworking-doors serve to drop the roasted oreinto the arched chamber 21 under the sole. These orifices are closed during the heating by means of the cast-iron plates. The orc is charged, and the work is effected through the two doors each of which is divided into two entirely distinct parts, at the level of the cast-iron plates, which separate the ore from the flames. The arrangement is clearly shown in fig. 5. The mode of closing these doors is not shown in these figures, because there is nothing peculiar in it, and any device maybe used that is deemed most suitable. The lower part of each of the two doors is used for thecharging and the working of the ore. The upper portion above the plates has-no other use than to allow the examination of the plates, and to facilitate the packing of the joints during the operation; 7

The door Q, in figs. 1 and 3, is not used during the operation, and ought to be hermetically closed. It is placed in a brick block,which I term a temporary block, it being necessary to build and demolish it at will without starting or disturbing the arch or an Y other part of the furnace. ,The objectof this arrangement is as follows: It may happen that the plates become warped or worn outwhile the furnace is in good condition. It is, therefore, essential thtFt the plates can be taken out and others substituted without demolishing the arch. In such case it is only necessary to demolish the temporary block, whose width is greater th'- that of a single plate, and all the plates can be taken out successively by means of hooks or pincors, and new plates can be substituted, after which the temporary block can be rebuilt, and the furnace is thus put in working condition with great economy, and in a short space of time The furnace with two fire-chambersis shownin Sheet III, in which- 1 Figure'1 represents a horizontal section on line 1 2 3 .4 5 6, fig. 2, i. c., a little below the plate as to the sole and fire chambei and a little above the steam-pipes ns to the bridge. I

Figure 2 is a vertical section on line 7-8, fig. 1.

Figure 3 is a transverse section on lino 9-10, fig. 1, through the centre of the working-doors.

Figure 4 shows 'on an enlarged scale plane view of the plates which scparate the ore from the flames.

The two fire-chambcrsffare separated by a brick pier, a, fig. 1, which is extended, reduced in thickness the width of the firc'bridgqand reaches upward to the arch. The fuel is charged through the two doorspp, and the ait undcrncath the grate is admitted, as in the furnace previously described. I The arch which covers the whole furnace is cylindrical, and abuts on the piers in m. The side walls of the furnace, in which-tho working-doors are placed, should be constructed independently of the arch, so that they can be demolished and rebuilt at will, without injuring the'arch, whenever it is necessary to withdraw or replace one or more plates. The flames from the two firechambers first heat the steam which circulates-in the pipes t t t" t, and pass between the arch and the plates, and heat these plates directly and by reverberation. They then pass through five vertical lines u-u into five horizontal flues 0 0, and are then conveyed into the chimney through the line R. This arrangement allows of the utilization of part-of the heat; of thefiame-for the heating of the sole. Steam is brought under the plates at about 205' above the sole through the horizontal pipes A A, whose extremities are secured in brick masonry B placed about the middle of,the length of the fire-bridge. Each of these pipes is pierced along its whole length with one flat-mouthed orifice, which is about one centimctrein width. Steam is then injected upon the ore in a regular sheet. The four steam-superhcating pipes constitute two distinct systems, t t t t. They are sixteen centimetres in diameter, and traverse both the two side walls of the furnace at the central block a. The elbows which unite the pipes are enclosed in boxc B B, whose sides are made of sheet iron. The two boxes are filled with sand'to prevent loss of heat. Steam from the boiler passes into the two pipes t t-; from the pipe tit passes into the pipe t, and thence into the pipe A, while the steam from t follows pipe t, and thence passes into pipe A. The excess of steam and the gaseous products of the action of the steam are carried olf through the five openings a into the lines through which the flames pass. The draught is regulated by a register placed on top of the chimney, or in a side flue, as shown'at T, figs. 1 and 2. The charging of theorc, the working, and the repairing of the joints between the plates, are effected through the doors P P, the arrangcmentof which has been described in the preceding furnace. I

3. Revcrberatingi furnace without cast-iron plates. The drawings in Sheet IV'represent two rcvcrberating furnaces which are like that described in my 1864 patent. They difi'cr from it, however, in one essential point, which consists in the method of superheating the steam, and in the mode of injecting the steam upon the ore.

In comparing the drawings hereunto annexed with those of my patent of 1864, there will be found another difi'crencc, 2142., the suppression of the chamber for condcnsingthc products derived from the action of the steam on the ore. This chamber is of use only in case the ore to be heated contains a large proportion of arsenic and antimony.

Figures 1, 2, and 3 represent a reverberating furnace heated by mineral coal or lignitc.

Figures 4 and 5 represent a reverberating wood-furnace.

Fig. 1 represents a horizontal section on the line 1 2 3 4-5 6, fig. 2, and

Fig. i! is a vertical section on line 7-8, fig. 1.

Fig. is a vertical section of the chute a, through which the ore is charged on thograte, After charging the grate the chute is closed with the fuel itself, as is done in paddling-furnaces, kc.

"he air arrives at the grate through the orifice A, which isas wide as the fire-chamber. In some cases it may be useful to partially close this opening by adopting the arrangement previously indicated in reference to wood-furnaces. The flames heat the pipes at t t" t', in which the steam circulates. and following the arch,

mass

pass into the chimney through two lines a c. The charging of the fuel on the grate is to be regulated in such manner that the flame should not be oxidizing. The steam from the boiler follows pipes t t t" t, arranged as in the furnace with one fire-chamber, previously described, and passes into the tube T, which is placed a little above the sole. This tube is provided with a horizontal flat-mouthed orifice, through which steam is spread in a regular sheet uponthe entire solo. The height of this opening is about one centimetre. The two doors M M are used for working and charging, but the charging may also be effected through a hopper above the arch. The two orifices 'm m which are placed in front of the doors serve to drop the roasted ore into the arched chamber V underneath the sole. They are closed during the operation by means of iron plates. The draught is regulated by means of a register on the top ofjthe chimney or in the flue at R, as shown in fig. 2. The reverberating wood-furnace is shown in fig. 4, in horizontal section on line 1 2 3 4 5 6, fig. 5. I'

Fig. 5 is a vertical section on the line 7-8, fig. 4.

This furnace only differs from the'one preceding in the arrangement of the door for charging the fuel, and in the arrangement ofthe openingthrough which the air passes to the grate. These arrangements are those which havebeen previously indicated in the furnace with cast-iron plates and one fire-chamber.

II. Amalgamation. The-ore which has been roasted by meansof superheated steam, contains gold and silver in a natural state, the other metals, copper, lead, zinc, &c., all in the state of oxides. The earthy gauge, however, has undergone no appreciable change. In order to extract the gold and silver from this roasted ore, it is only necessary to produce sutiiciently intimate and prolonged contact with the requisite quantity of mercury. It is in this that the essential advantage and characteristic of my process consist. Theamalgamation may thus be effected in any of the knownapparatus. In. my 1864 patent I have only shown revolving tune or barrels, but I would observe that it may be best to adopt in each locality such apparatus usare there usually employed, The salt, the magistral, and all other reagents, with the exception of water, are dispensed with. Other apparatus, such as have never been used for amalgamation, may be employed in this operation. I would mention, for instance, the arustrusand vertical millstones revolving in a horizontal annular bed. These apparatus are generally usedfor grinding purposes, and will now proceed to describe the manner in which they may be adapted tothe amalgamating process, taking as an example the vertical millstone.- ,The dimensionsof the\bed and millstones may be varied according to the quantity of ore to be treated at one operationv The upper limit' is determined for each establishment by the motive-power, and the dimensions of the material employed.

The operation is divided into three stages.-

First stage. The roastedore is charged on the bottom of the bed with a quantity of mercury, thirty times, more or less, the weight of gold and silver which the ore should contain. The millstones are rotated for about I I four hours, at least, with such rapidity as not to throw the mercury and ore out of the bed. This first stage of the amalgamation has for its object the minute division of the mercury, and consequent intimate and pr.olonged contact ofall-the gold and silver grains .with the mercury. For certain ores, if four hours do not sufli'ce to reduce the mereuryinto indiscernible powder, the trituration should be prolonged in a dry state until the desired effect is produced.

Second stage. The mixture of ore and. mercury is profusely moistened with water until the matter acquires the consistency of very soft paste. The millstones again revolve at least four hours, adding from time to time water to replace that which evaporates, and maintain the-paste at the same degree of consistency. During this stage the mercury changes into very small and brilliant grains, and the combination of the ore and silver with the mercury is completed. Nothing now remains to be done but to reunite the mercury with' the amalgam. This is partially done in the third or last stage of the amalgamation.

Third stage. In continuing to revolve the millstones at the same velocity,'the matter is reduced to a liquid paste by adding to it more water. In about three or four hours the mercury will appear in large globules, holding the amalgam in solution. The water is then poured into the bucketsand carried to the ordinary concentration. This new process of amalgamation is as effectual as the best process heretofore known,-and allows at the same time of a large amount of ore being operated upon at onetime.

Summing up the characteristic points of the present invention, which'constitute the improvements upon that patented by me in 1864, it will be seen that they consistin the'following features, which I thereupon claim, and desire to secure by Letters Patent:

1. The roasting of silver and gold .ore by superheated steam in the manner as herein described, that is, by separating the ore from the flames by the interposition of cast-iron plates, and by superheating the steam in the furnace itself, substantially asshown and set forth.

2. The reverberating furnace, substantially as herein described, when proyided with steam-pipes on or about the fire-bridge for discharging steam upon the sole, whether such furnace be arranged for burning vegetable or mineral fuel, as set forth. e

3. The arrangement,'herein shown and described, of a double furnace, or of a single furnace with two fire. chambers, together with the use of cast-iron plates at the level of the fire-bridge, to separate the flames from the ore, substantially as set forth. I

4. The arrangement of the furnace, herein shown and described, in which superheated steam is made to impinge upon the ore, when separated from the flames of the fire-chamber.

5. The method of amulgamating the roasted ore, without the adoption of any reagents, in apparatus of ordinary or suitable construction, substantially as herein shown and set forth.

In testimony whereof, I have signed my name to this specification before two subscribing witnesses.

, I L. E. RIVOT.

Witnesses:

E. Brennan-s,

J. Gurntaanon. 

